package com.wlx.filter;


import com.alibaba.fastjson.JSONObject;
import com.github.pagehelper.util.StringUtil;
import com.wlx.pojo.Result;
import com.wlx.utils.JwtUtils;
import lombok.extern.slf4j.Slf4j;
import org.springframework.util.StringUtils;

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;

@Slf4j
@WebFilter(urlPatterns = "/*")
public class LoginCheckFilter implements Filter {
    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {

        HttpServletRequest req = (HttpServletRequest) servletRequest;
        HttpServletResponse resp = (HttpServletResponse) servletResponse;

        //1、获取请求url
        String url = req.getRequestURL().toString();
        log.info("请求的url:{}",url);

        //2、判断请求的url是否包含login，如果包含，说明是登录操作，放行
        if (url.contains("login")){
            log.info("登录操作，方行---");
            filterChain.doFilter(servletRequest,servletResponse);
            return;
        }

        //3、获取请求头中的令牌 token
        String jwt = req.getHeader("token");

        //4、判断令牌是否存在，未存在，返回错误结果（未登录）
        if (!StringUtils.hasLength(jwt)){
            log.info("请求头token为空，返回未登录信息");
            Result error = Result.error("NOT_LOGIN");
            //手动转对象json    ----->阿里巴巴fastJSON
            String notLogin = JSONObject.toJSONString(error);
            resp.getWriter().write(notLogin);
            return;
        }

        //5、解析token如果解析失败返回错误结果（未登录）
        try {
            JwtUtils.parseJWT(jwt);
        }catch (Exception e){  //jwt解析失败
            e.printStackTrace();
            log.info("解析令牌失败，返回未登录错误信息");
            Result error = Result.error("NOT_LOGIN");
            //手动转对象json    ----->阿里巴巴fastJSON
            String notLogin = JSONObject.toJSONString(error);
            resp.getWriter().write(notLogin);
            return;
        }

        //6、放行
        log.info("令牌合法，放行");
        filterChain.doFilter(servletRequest,servletResponse);
    }
}
